1. Field of the Invention
The present invention relates to the field of handling equipment and more specifically, to the field of equipment for transferring articles from one line such as a conveyor line to a delivery region such as a second conveyor line.
2. Prior Art
In various aspects of the processing and packaging industries such as food and beverage processing and packaging, it becomes desirable to automatically selectively transfer articles from one conveyor to a second conveyor based upon some quantitive or qualitive characteristic of the article being transferred in comparison to the articles not being so transferred. By way of specific example, U.S. Pat. No. 3,009,572 discloses various embodiments of apparatus for sorting articles, the apparatus specifically disclosed therein being adapted for segregating or sorting articles according to weight classifications, and rejecting from a stream of articles those articles which are over or under the limits of a predetermined weight range. That system uses a special relatively wide conveyor-like apparatus which has a plurality of transfer slides thereon onto which the weighed articles pass from another conveyor. The slides normally are centered in the apparatus and guided by appropriate guides therefor so as to remain centered, ultimately being delivered at the center of the end of the conveyor-like apparatus. If however, an article is overweight, the system is controlled so that the slides carrying the article are initially deflected in a first direction from center at a particular position along the path of travel, at which position the slides pick up fixed guides which further guide and move the slides to the first side of the conveyor-like apparatus for delivery at the first side of the end of the conveyor-like structure. If, on the other hand, a particular article is underweight, the slides will be deflected at the control point toward the second side of the conveyor-like apparatus where additional fixed slides will guide the slides toward the second side of the conveyor-like apparatus for delivery of the article adjacent the second side of the conveyor-like apparatus at the end thereof, whereby proper weight, overweight and underweight articles will be delivered at three distinct positions at the end of the apparatus. All slides are returned to the central position by appropriate fixed guides prior to their receipt of further articles to be sorted.
U.S. Pat. No. 2,936,059 discloses an all automatic apparatus for handling curved surface articles. That apparatus includes slides which operate in a similar manner, though rather than the slides having the articles to be sorted resting thereon, the slides of the '059 patent project in a direction perpendicular to the path of travel of a conveyor containing the articles to be transferred and when extended, engage the articles from the side to slide them off that conveyor into other apparatus. The system of U.S. Pat. No. 3,471,012 is very similar to the two mentioned patents, having the side transfer characteristics of the '059 patent and the selective transfer of single articles of the '572 patent.
The advantage of the general type of transfer device or rejector of the foregoing three patents is that the transfer of articles from a given path to a second path is accomplished over some extended length of travel (and according, over some significant period of time) as opposed to being done very quickly, such as in the systems disclosed in U.S. Pat. Nos. 3,270,881 and 3,133,640, wherein articles which are proceeding on a conveyor but are to be rejected are merely pushed sideways by the momentary actuation of an actuator at a particular point along the article's path of travel. The characteristically longer time of the transfer of systems such as are disclosed in the '012, the '059 and the '572 patents results in a gentler handling of the articles being transferred, an advantage when handling fragile articles such as glass bottles. Alternatively, such equipment is generally capable of higher speed operation than equipment affecting the transfer on a more violent basis because the smoothness of the transfer is more compatible with higher speed. However, neither the system of the '012 patent nor of the '572 patent is suitable for particularly high speeds, as the selective actuation of the pusher members is by way of actuators which require a substantial length of time for actuation in comparison to the frequency with which the pusher members would pass thereby in high speed machines.